refactor into lib/app

lib/CMakeLists.txt

@@ -0,0 +1,13 @@
+# ./lib/CMakeLists.txt
+cmake_minimum_required(VERSION 3.10)
+project(gddr6_lib)
+set(LIB_SOURCES src/gddr6.c)
+
+# Static library (libgddr6)
+add_library(gddr6_lib STATIC ${LIB_SOURCES})
+target_include_directories(gddr6_lib PUBLIC include)
+
+set_target_properties(gddr6_lib PROPERTIES
+    OUTPUT_NAME "gddr6" # rename libgddr6_lib.a to libgddr6.a
+    ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)